Production of CFC refrigerants became illegal on January 1, ____________________.

Cooling occurs in a direct- expansion vapor compression refrigeration system when:

When a technician works for a company in which the technician does not have a financial interest, the technician does not have to be certified.

The small amount of refrigerant released when removing gauge hoses from the system is called ____________________.

Refrigerants that damage the ozone layer contain an element called ____________________.

Why is stratospheric ozone so important to our environment?

To clean refrigerant by the use of filter dryers is called ____.

HCFC-based blends work best with ____________________ lubricants, while HFC-based blends work best with ester lubricants.

What is the process by which the catalyst and accelerator begin to cure?

Spatulation is the action used to mix alginate impression material by hand.